The clinical approach towards chondrosarcoma

The Role of Deubiquitinating Enzymes in Primary Bone Cancer

Bone is a living, intricate, and dynamic tissue providing locomotion and protection of the body. It also performs hematopoiesis and mineral homeostasis. Osteosarcoma (OS), Ewing sarcoma (ES), and chondrosarcoma (CS) are primary bone cancers. OS and ES mostly develop in younger individuals, and CS generally develops in adults. Ubiquitination regulates numerous cellular processes. The deubiquitinating enzymes (DUBs) detach the ubiquitin molecules from the ubiquitin labeled substrate, altering ubiquitinated protein functions and regulating protein stability via various signaling pathways. Protein homeostasis and bone remodeling are both crucially influenced by the UPS. Recently, there have been several reports on DUBs involved in bone homeostasis and various bone disorders through the regulation of osteoblasts and osteoclasts via NF-κB, Wnt/β-catenin, TRAF6, TGFβ, ERK1/2, and PI3K/Akt pathways. However, DUBs regulating function in bone homeostasis is still in its infancy. Here, we summarized several recent identifications on DUBs, with a focus on their role in bone cancer progression. Therefore, the study attempts to summarize association with the expression level of DUBs as key factors driving bone cancers and also provide new insights on DUBs as key pharmacologic targets for bone cancer therapeutics.

Nasal clear cell chondrosarcoma in a dog

An intranasal tumour was diagnosed in a 5-year-old male neutered crossbreed dog following a 6-8 week history of intermittent epistaxis and nasal discharge. Computed tomography identified a mass in the right nasal cavity. Histologically, the mass was composed of sheets and indistinct clusters of predominantly clear or vacuolated round to polygonal cells; periodic acid-Schiff staining revealed glycogen granules within some tumour cells. Immunohistochemical labelling revealed that the tumour cells were immunopositive for vimentin and S100 and negative for pancytokeratin, Melan-A and PNL2, supporting a diagnosis of a clear cell variant of chondrosarcoma (CCC). Although the dog was treated with meloxicam, the owners opted for euthanasia 9 days after presentation. Considering that there is only one other reported case of a suspected CCC in a dog, also in the nasal cavity, this could represent a species-specific predilection site of this rare canine neoplasm.

Chondrosarcoma of the Mobile Spine in the Elderly: A National Cancer Database Study

BACKGROUND

The current research on geriatric patients with spinal chondrosarcoma is limited. This study aimed to investigate the demographics, patterns of care, and survival of geriatric patients with chondrosarcoma of the mobile spine.

METHODS

The National Cancer Database was queried from 2008 to 2018 for geriatric patients (60-89 years) with chondrosarcoma of the mobile spine. The primary outcome of this study was overall survival. The secondary outcome was treatment utilization patterns. Survival analyses were conducted using log-rank tests and Cox proportional hazards regressions. Logistic regression models were utilized to assess correlations between baseline variables and treatment utilization.

RESULTS

The database retrieved 122 patients. While 43.7% of the patients presented with tumors exceeding 5 cm in size, the incidence of regional lymph node involvement or distant metastases was relatively low, affecting only 5% of the patients. Furthermore, 22.3% of the patients had tumors graded as 3-4. The 5-year overall survival rate was 52.9% (95% confidence interval: 42-66.6). The mortality risk was significantly associated with age, tumor grade and stage, and treatment plan. Most patients (79.5%) underwent surgery, while 35.9% and 4.2% were treated with radiotherapy and chemotherapy, respectively. Age, race, comorbidities, geographical region, tumor stage, and healthcare facility type significantly correlated with treatment utilization.

CONCLUSIONS

Surgical resection significantly lowered the mortality risk in geriatric patients with spinal chondrosarcomas. Demographic and geographical factors significantly dictated treatment plans. Further studies are required to assess the role of radiotherapy and chemotherapy in treating these patients in the modern era.

Incidence and survival outcomes of patients with high-grade appendicular bone sarcoma and isolated regional lymph node metastasis: A national cohort database study

BACKGROUND

While distant metastases in primary bone sarcomas have been extensively studied, the impact of isolated regional lymph node (LN) metastasis on survival remains unknown. In patients with primary bone sarcomas, we sought to assess the prevalence of isolated regional LN metastasis and the survival of this population.

METHODS

A total of 6651 patients with histologically-confirmed high-grade osteosarcoma, Ewing sarcoma, or chondrosarcoma were retrieved from the SEER database. We defined four subgroups for our analysis: localized disease (N0 M0), isolated regional LN metastasis (N1 M0), isolated distant metastasis (N0 M1), and combined regional LN and distant metastasis (N1 M1). Disease-specific survival (DSS) was assessed using the Kaplan-Meier method.

RESULTS

Prevalence of isolated regional LN metastasis (N1 M0) was highest in Ewing sarcoma (27/1097; 3.3 %), followed by chondrosarcoma (18/1702; 1.4 %) and osteosarcoma (26/3740; 0.9 %). In all three histologies, patients with isolated regional LN metastasis had a worse 2-year, 5-year, and 10-year DSS than those with localized disease. Chondrosarcoma patients with isolated regional LN (N1 M0) metastasis had a significantly higher DSS in comparison to those with only distant metastasis (N0 M1) at the 5- and 10-year marks; for osteosarcoma and Ewing sarcoma, only a pattern towards higher survival was seen. Risk factors for presenting isolated regional LN metastasis included tumor location in lower-limb (OR = 2.01) or pelvis (OR = 2.49), diagnosis of Ewing sarcoma (OR = 2.98), and tumor >10 cm (OR = 1.96).

CONCLUSIONS

Isolated regional LN metastases in primary bone sarcomas is an infrequent presentation associated with worse survival than localized disease.

LEVEL OF EVIDENCE

III.

Limb Salvage in Chondrosarcoma of the Proximal Humerus: A Case Report

Chondrosarcoma is the third most common primary malignant bone tumor. The proximal humerus is the most common site. Since it is resistant to chemotherapy and radiotherapy, the mainstay of treatment is surgery. Due to the extensive involvement of long bones, it requires reconstruction with either a prosthetic implant or bone graft. We present a case of a 43-year-old female who presented with chondrosarcoma involving 15 cm of humerus. The patient was managed with the resection of 15 cm of humerus and reconstruction with the same resected bone after autoclaving. It was secured with long fixation resulting in arthrodesis of the glenohumeral joint. The patient was followed for one year and there was evidence of callus formation by ultrasound and computed tomography (CT) scan.

Sinonasal Chondrosarcoma With Unusual Orbital Invasion

A case is presented of a 43-year-old male with a chronic history of progressive nasal obstruction and epiphora. MRI confirmed a heterogeneous mass involving the middle and superior turbinates with T2 hyperintense and calcified components, with extension into the inferomedial orbit. Tissue biopsy revealed a grade 2 chondrosarcoma of the conventional subtype. Endonasal wide local resection of the lesion was performed with clear margins. The patient had no functional sequelae and will undergo routine surveillance.

Targeted treatment of chondrosarcoma with a bacteriophage-based particle delivering a secreted tumor necrosis factor-related apoptosis-inducing ligand

Chondrosarcoma (CS) is a malignant cartilage-forming bone tumor that is inherently resistant to chemotherapy and radiotherapy, leaving surgery as the only treatment option. We have designed a tumor-targeted bacteriophage (phage)-derived particle (PDP), for targeted systemic delivery of cytokine-encoding transgenes to solid tumors. Phage has no intrinsic tropism for mammalian cells; therefore, it was engineered to display a double cyclic RGD4C ligand on the capsid to target tumors. To induce cancer cell death, we constructed a transgene cassette expressing a secreted form of the cytokine tumor necrosis factor-related apoptosis-inducing ligand (sTRAIL). We detected high expression of αvβ3 and αvβ5 integrin receptors of the RGD4C ligand, and of the TRAIL receptor-2 in human CS cells (SW1353), but not in primary normal chondrocytes. The RGD4C.PDP-Luc particle carrying a luciferase reporter gene, Luc, effectively and selectively mediated gene delivery to SW1353 cells, but not primary chondrocytes. Transduction of SW1353 cells with RGD4C.PDP-sTRAIL encoding a human sTRAIL, resulted in the expression of TRAIL and subsequent cell death without harming the normal chondrocytes. Intravenous administration of RGD4C.PDP-sTRAIL to mice with established human CS resulted in a decrease in tumor size and tumor viability. Altogether, RGD4C.PDP-sTRAIL can be used to target systemic treatment of CS with the sTRAIL.

FBXO22 is a potential therapeutic target for recurrent chondrosarcoma

Chondrosarcoma (CHS) is a malignant bone tumor with insensitivity to both radiotherapy and chemotherapy, and a high recurrence rate. However, the latent mechanism of recurrent CHS (Re-CHS) remains elusive. Here, we discovered that FBXO22 was highly expressed in clinical samples of Re-CHS. FBXO22 played a significant role in various cancers. However, the role of FBXO22 in Re-CHS remained unclear. Our research demonstrated that suppressing FBXO22 abated the proliferation and migration of CHS cells and facilitated their apoptosis. In addition, suppressing FBXO22 raised the expression of PD-L1 in Re-CHS. All these findings provide new evidence for using FBXO22 and PD-L1 as combined targets to prevent and treat Re-CHS, which may prove to be a novel strategy for immunotherapy of CHS, especially Re-CHS.

Advances in the Synthesis of Biologically Active Quaternary Ammonium Compounds

This review provides a comprehensive overview of recent advancements in the design and synthesis of biologically active quaternary ammonium compounds (QACs). The covered scope extends beyond commonly reviewed antimicrobial derivatives to include synthetic agents with antifungal, anticancer, and antiviral properties. Additionally, this review highlights examples of quaternary ammonium compounds exhibiting activity against protozoa and herbicidal effects, as well as analgesic and anesthetic derivatives. The article also embraces the quaternary-ammonium-containing cholinesterase inhibitors and muscle relaxants. QACs, marked by their inherent permanent charge, also find widespread usage across diverse domains such as fabric softeners, hair conditioners, detergents, and disinfectants. The effectiveness of QACs hinges greatly on finding the right equilibrium between hydrophilicity and lipophilicity. The ideal length of the alkyl chain varies according to the unique structure of each QAC and its biological settings. It is expected that this review will provide comprehensive data for medicinal and industrial chemists to design and develop novel QAC-based products.

A CT-based radiomics nomogram for predicting histologic grade and outcome in chondrosarcoma

OBJECTIVE

The preoperative identification of tumor grade in chondrosarcoma (CS) is crucial for devising effective treatment strategies and predicting outcomes. The study aims to build and validate a CT-based radiomics nomogram (RN) for the preoperative identification of tumor grade in CS, and to evaluate the correlation between the RN-predicted tumor grade and postoperative outcome.

METHODS

A total of 196 patients (139 in the training cohort and 57 in the external validation cohort) were derived from three different centers. A clinical model, radiomics signature (RS) and RN (which combines significant clinical factors and RS) were developed and validated to assess their ability to distinguish low-grade from high-grade CS with area under the curve (AUC). Additionally, Kaplan-Meier survival analysis was applied to examine the association between RN-predicted tumor grade and recurrence-free survival (RFS) of CS. The predictive accuracy of the RN was evaluated using Harrell's concordance index (C-index), hazard ratio (HR) and AUC.

RESULTS

Size, endosteal scalloping and active periostitis were selected to build the clinical model. Three radiomics features, based on CT images, were selected to construct the RS. Both the RN (AUC, 0.842) and RS (AUC, 0.835) were superior to the clinical model (AUC, 0.776) in the validation set (P = 0.003, 0.040, respectively). A correlation between Nomogram score (Nomo-score, derived from RN) and RFS was observed through Kaplan-Meier survival analysis in the training and test cohorts (log-rank P < 0.050). Patients with high Nomo-score tumors were 2.669 times more likely to suffer recurrence than those with low Nomo-score tumors (HR, 2.669, P < 0.001).

CONCLUSIONS

The CT-based RN performed well in predicting both the histologic grade and outcome of CS.

New advances in the treatment of chondrosarcoma under the PD-1/PD-L1 pathway

ABSTRACT

Bone sarcomas encompass a group of spontaneous mesenchymal malignancies, among which osteosarcoma, Ewing sarcoma, chondrosarcoma, and chordoma are the most common subtypes. Chondrosarcoma, a relatively prevalent malignant bone tumor that originates from chondrocytes, is characterized by endogenous cartilage ossification within the tumor tissue. Despite the use of aggressive treatment approaches involving extensive surgical resection, chemotherapy, and radiotherapy for patients with osteosarcoma, chondrosarcoma, and chordoma, limited improvements in patient outcomes have been observed. Furthermore, resistance to chemotherapy and radiation therapy has been observed in chondrosarcoma and chordoma cases. Consequently, novel therapeutic approaches for bone sarcomas, including chondrosarcoma, need to be uncovered. Recently, the emergence of immunotherapy and immune checkpoint inhibitors has garnered attention given their clinical success in various diverse types of cancer, thereby prompting investigations into their potential for managing chondrosarcoma. Considering that circumvention of immune surveillance is considered a key factor in the malignant progression of tumors and that immune checkpoints play an important role in modulating antitumor immune effects, blockers or inhibitors targeting these immune checkpoints have become effective therapeutic tools for patients with tumors. One such checkpoint receptor implicated in this process is programmed cell death protein-1 (PD-1). The association between PD-1 and programmed cell death ligand-1 (PD-L1) and cancer progression in humans has been extensively studied, highlighting their remarkable potential as biomarkers for cancer treatment. This review comprehensively examines available studies on current chondrosarcoma treatments and advancements in anti-PD-1/PD-L1 blockade therapy for chondrosarcoma.

The Rat Sarcoma Virus (RAS) Family of Proteins in Sarcomas

The rat sarcoma virus (RAS) protein family plays a crucial role in facilitating communication both within and between cells, thereby governing fundamental cellular processes such as growth, survival, and differentiation. The RAS family comprises four members of small GTPases, namely Harvey RAS (H-RAS), Kirsten RAS (K-RAS, two splice variants, 4A and 4B), and Neuroblastoma RAS (N-RAS), and these are encoded by three cellular RAS genes. Mutations in these genes play a significant role in cancer development and progression. Accordingly, here we review and discuss currently available literature about the fate and function of the RAS family of proteins in sarcomas.

Pathological fracture treated with total femoral replacement in a case of chondrosarcoma involving the entire-length femoral shaft

INTRODUCTION AND IMPORTANCE

We here present a case of chondrosarcoma of the diaphysis of the femur with extensive involvement of the length of the bone and with the pathological fracture at the mid-shaft level. Total femur replacement was done in this case with a bipolar head and repair of abductors and hip flexors to the implanted prosthesis.

CASE PRESENTATION

An elderly female in her late 60s presented to the trauma department with sudden onset pain and inability to bear weight on her left lower limb following a trivial slip and fall. The Radiographs revealed a pathological spiral mid-shaft displaced fracture of the femur with an extensive mixed lesion throughout the femur. Magnetic Resonance imaging revealed involvement of more than 90% of the femur with lesion extension into the quadriceps and hamstrings. Histopathology confirmed grade-II conventional chondrosarcoma. Metastatic work-up showed no distant spread. Wide-local resection and total femur endo-prosthetic reconstruction were done. No recurrence or infection was evident at the 18-month follow-up. In elderly non-metastatic pathological fractures, limb salvage with endo-prosthetic reconstruction can be a preferred treatment.

CLINICAL DISCUSSION

This case is unique in describing a rare presentation of chondrosarcoma of the diaphysis of the femur, which eventually landed in a pathological fracture. The fracture may increase the tumour's aggressiveness, but wide-margin resection should be the mainstay treatment for primary or recurrent chondrosarcoma, irrespective of pathological fracture.

CONCLUSION

In well-indicated cases (no distant spread - N0M0 disease), Total Femur Replacement (TFR) is an excellent option for limb salvage in tumours with extensive involvement of the femur.

X-rays radiomics-based machine learning classification of atypical cartilaginous tumour and high-grade chondrosarcoma of long bones

BACKGROUND

Atypical cartilaginous tumour (ACT) and high-grade chondrosarcoma (CS) of long bones are respectively managed with active surveillance or curettage and wide resection. Our aim was to determine diagnostic performance of X-rays radiomics-based machine learning for classification of ACT and high-grade CS of long bones.

METHODS

This retrospective, IRB-approved study included 150 patients with surgically treated and histology-proven lesions at two tertiary bone sarcoma centres. At centre 1, the dataset was split into training (n = 71 ACT, n = 24 high-grade CS) and internal test (n = 19 ACT, n = 6 high-grade CS) cohorts, respectively, based on the date of surgery. At centre 2, the dataset constituted the external test cohort (n = 12 ACT, n = 18 high-grade CS). Manual segmentation was performed on frontal view X-rays, using MRI or CT for preliminary identification of lesion margins. After image pre-processing, radiomic features were extracted. Dimensionality reduction included stability, coefficient of variation, and mutual information analyses. In the training cohort, after class balancing, a machine learning classifier (Support Vector Machine) was automatically tuned using nested 10-fold cross-validation. Then, it was tested on both the test cohorts and compared to two musculoskeletal radiologists' performance using McNemar's test.

FINDINGS

Five radiomic features (3 morphology, 2 texture) passed dimensionality reduction. After tuning on the training cohort (AUC = 0.75), the classifier had 80%, 83%, 79% and 80%, 89%, 67% accuracy, sensitivity, and specificity in the internal (temporally independent) and external (geographically independent) test cohorts, respectively, with no difference compared to the radiologists (p ≥ 0.617).

INTERPRETATION

X-rays radiomics-based machine learning accurately differentiates between ACT and high-grade CS of long bones.

FUNDING

AIRC Investigator Grant.

Decoupling NAD+ metabolic dependency in chondrosarcoma by targeting the SIRT1-HIF-2α axis

Chondrosarcomas represent the second most common primary bone malignancy. Despite the vulnerability of chondrosarcoma cells to nicotinamide adenine dinucleotide (NAD+) depletion, targeting the NAD+ synthesis pathway remains challenging due to broad implications in biological processes. Here, we establish SIRT1 as a central mediator reinforcing the dependency of chondrosarcoma cells on NAD+ metabolism via HIF-2α-mediated transcriptional reprogramming. SIRT1 knockdown abolishes aggressive phenotypes of chondrosarcomas in orthotopically transplanted tumors in mice. Chondrosarcoma cells thrive under glucose starvation by accumulating NAD+ and subsequently activating the SIRT1-HIF-2α axis. Decoupling this link via SIRT1 inhibition unleashes apoptosis and suppresses tumor progression in conjunction with chemotherapy. Unsupervised clustering analysis identifies a high-risk chondrosarcoma patient subgroup characterized by the upregulation of NAD+ biosynthesis genes. Finally, SIRT1 inhibition abolishes HIF-2α transcriptional activity and sensitizes chondrosarcoma cells to doxorubicin-induced cytotoxicity, irrespective of underlying pathways to accumulate intracellular NAD+. We provide system-level guidelines to develop therapeutic strategies for chondrosarcomas.

Chondrosarcoma of the Femur: Is Local Recurrence Influenced by the Presence of an Extraosseous Component?

BACKGROUND

Chondrosarcoma (CS) is the second most common surgically treated primary malignancy of the bone. The current study explored the effect of the margin and extraosseous tumor component in CS in the femur on local recurrence (LR), LR-free survival (LRFS), and disease-specific survival (DSS).

METHODS

Among 202 patients, 115 were in the proximal extremity of the femur, 4 in the corpus of the femur, and 83 in the distal extremity of femur; 105 patients had an extraosseous tumor component.

RESULTS

In the Kaplan-Meier analysis, factors significant for decreased LRFS were the extraosseous tumor component (p < 0.001), extraosseous tumor component arising from the superior aspect (p < 0.001), histological grade (p = 0.031), and narrow surgical margin < 3 mm (p < 0.001). Factors significantly affecting DSS were the histological grade (p < 0.001), extraosseous component (p < 0.001), LR (p < 0.001), metastases (p < 0.001), and surgical margin (p < 0.001).

CONCLUSIONS

In CS of the femur, the presence of an extraosseous tumor component has a predictive role in LRFS, and extraosseous tumor component arising from the superior aspect was significant for decreased LRFS. Wide margins were more commonly achieved when the tumor had only an intraosseous component, and the rate of LR was significantly higher in cases with an extraosseous tumor component. When the extraosseous component arose from the superior aspect of the femur, LR occurred more frequently despite achieving adequate margins.

Are IDH1 R132 Mutations Associated With Poor Prognosis in Patients With Chondrosarcoma of the Bone?

BACKGROUND

Because chondrosarcomas vary widely in their behavior, and because anticipating their behavior based on histology alone can be challenging, genetic markers represent an appealing area of inquiry that may help us refine our prognostic approaches. Isocitrate dehydrogenase (IDH) mutations are involved in the pathogenesis of a variety of neoplasms, and recently, IDH1/2 mutations have been found in the tissue of benign cartilage tumors as well as in conventional chondrosarcomas and highly aggressive dedifferentiated chondrosarcomas. However, their association with patient survival is still controversial.

QUESTIONS/PURPOSES

(1) What proportion of patients with chondrosarcomas carry IDH mutations, and which IDH mutations can be found? (2) Are any specific IDH mutations associated with poorer overall survival, metastasis-free survival, or local recurrence-free survival?

METHODS

Between April 2017 and December 2022, we treated 74 patients for atypical cartilaginous tumors or chondrosarcomas in a musculoskeletal tumor referral center. Patients were considered potentially eligible for the present study if the histologic diagnosis was confirmed by two expert soft tissue and bone pathologists following the current WHO classification, complete preoperative imaging and follow-up data were available, surgical excision was performed by sarcoma orthopaedic surgeons directed by a team leader, and the minimum follow-up was 2 years after surgical treatment unless the patient died. Data including sex, age, diagnosis, grade, type of operation, local recurrence, metastasis, and oncologic follow-up were recorded. Forty-one patients (55%) were eligible for the study. For each patient, DNA was extracted and quantified from paraffin-embedded sections of tumor tissue, and the mutational status of IDH1 (codons 105 and 132) and IDH2 (codons 140 and 172) genes was assessed. Of those, 56% (23 of 41) of patients had adequate DNA for analysis of IDH mutations: 10 male and 13 female patients, with a median age of 59 years (range 15 to 98 years). There were 22 conventional chondrosarcomas (8 atypical cartilaginous tumors, 11 Grade 2, and 3 Grade 3) and 1 dedifferentiated chondrosarcoma. Stage was IA in 3 patients, IB in 5, IIA in 1, IIB in 13, and III in 1, according to the Musculoskeletal Tumor Society classification. At a median follow-up of 3.5 years (range 4 months to 5.6 years), 14 patients were disease-free, 2 were alive with disease, and 7 died (3 within 2 years from surgery). Eight patients had metastases, and 7 developed local recurrence. We determined the proportion of patients who carried IDH mutations, and compared patients with and without those mutations in terms of overall survival, metastasis-free survival, and local recurrence-free survival using Kaplan-Meier curves.

RESULTS

Six patients showed wild-type IDH genes, and 17 had IDH mutations (12 had IDH1 R132, 3 had IDH1 G105, and 2 had IDH2 R172). Overall survival at 2 years using the Kaplan-Meier estimator was lower in patients with an IDH mutation than in those with the wild-type gene (75% [95% confidence interval 50% to 99%] versus 100% [95% CI 100% to 100%]; p = 0.002). Two-year metastasis-free survival was also lower in patients with an IDH mutation than in those with the wild-type gene (33% [95% CI 7% to 60%] versus 100% [95% CI 100% to 100%]; p = 0.001), as was 2-year local recurrence-free survival (70% [95% CI 42% to 98%] versus 100% [95% CI 100% to 100%]; p = 0.02).

CONCLUSION

We found that IDH1 R132 mutations were negatively associated with the prognosis of patients with bone chondrosarcomas. Nevertheless, more extensive studies (such as multicenter international studies) are needed and advisable to confirm our observations in this preliminary small series. Moreover, evaluating mutational status in fresh samples instead of in paraffin-embedded sections could help to increase the number of patients with adequate DNA for analysis. If our findings will be confirmed, the evaluation of IDH mutational status in biopsy samples or resection specimens could be considered when stratifying patients, highlighting those who may benefit from more aggressive treatment (such as adjuvant chemotherapy) or closer follow-up.

LEVEL OF EVIDENCE

Level III, prognostic study.

[Surgical treatment of extensive metastatic tumor of the left ribs III-V and lung in 13 years after resection of cylindroma of the soft palate]

Metastatic chest lesion is rare in patients with soft palate tumors. We present a 52-year-old patient with metastatic lesion of the left ribs III-V and lung in 13 years after resection of cylindroma of the soft palate. The patient underwent successful chest reconstruction and atypical resection of the left lung. Isolation of the pleural cavity by xenopericardial patches and preoperative 3D CT modeled titanium implants meet all the requirements for maintaining the chest function. This approach also positively affects postoperative period and recovery. The above-described method of replacing chest defects is highly effective.

Clinico-Genomic Profiling of Conventional and Dedifferentiated Chondrosarcomas Reveals TP53 Mutation to Be Associated with Worse Outcomes

PURPOSE

Chondrosarcomas are the most common primary bone tumor in adults. Isocitrate dehydrogenase 1 (IDH1) and IDH2 mutations are prevalent. We aimed to assess the clinico-genomic properties of IDH mutant versus IDH wild-type (WT) chondrosarcomas as well as alterations in other genes.

EXPERIMENTAL DESIGN

We included 93 patients with conventional and dedifferentiated chondrosarcoma for which there were available clinical next-generation sequencing data. Clinical and genomic data were extracted and compared between IDH mutant and IDH WT chondrosarcomas and between TP53 mutant and TP53 WT chondrosarcomas.

RESULTS

IDH1 and IDH2 mutations are prevalent in chondrosarcoma (50.5%), more common in chondrosarcomas arising in the extremities, associated with higher age at diagnosis, and more common in dedifferentiated chondrosarcomas compared with grades 1-3 conventional chondrosarcoma. There was no difference in survival based on IDH mutation in univariate and multivariate analyses. TP53 mutation was the next most prevalent (41.9%) and is associated with worse overall survival and metastasis-free survival in both univariate and multivariate analyses. TP53 mutation was also associated with higher risk of recurrence following curative-intent surgery and worse survival among patients that presented with de novo metastatic disease.

CONCLUSIONS

IDH mutations are prevalent in chondrosarcoma though were not associated with survival outcomes in this cohort. TP53 mutations were the next most common alteration and were associated with worse outcomes.

Intraosseous conventional central chondrosarcoma does not metastasise irrespective of grade in pelvis, scapula and in long bone locations

Background

Histological grade has been regarded as the most important prognostic factor in conventional central chondrosarcoma. To evaluate whether the presence of an extraosseous tumour component is associated with a decreased metastasis-free survival or disease-specific survival and alternatively to develop a simple prognostic and clinical decision-making tool.

Material and methods

We searched two prospectively maintained international sarcoma centre databases for primary non metastatic central conventional chondrosarcomas of all grades in pelvis, scapula or long bone location, undergoing curative treatment, diagnosed between 2000 and 2020. Pre-treatment MRI scans were reviewed for the presence of an extraosseous mass. The metastasis-free survival (MFS) and disease-specific survival (DSS) were estimated by the Kaplan-Meier method from surgery to event, death or last follow-up.

Results

336 patients were identified between 2000 and 2020, undergoing surgical treatment for conventional central chondrosarcoma. 111 patients (33 %) had grade 1 tumours, 149 patients (44 %) had grade 2, and 76 patient (23 %) had grade 3 chondrosarcomas determined as the highest grade in the final resected specimen. An extraosseous soft tissue component was more frequent in higher grade tumours (p < 0.001) and present in 200 cases (60 %). None of the patients with an intraosseous tumour developed metastases or died of the disease. For patients with extraosseous tumour component, MFS was 92 % (95 % CI, 96-100) at 2-years and 74 % (95 % CI, 67-81) at 10-years and DSS was 91 % (95 % CI, 87-95) at 2-years and 75 % (95 % CI, 68-82) at 10-years. The MFS and DSS was significantly different (p < 0.001) for those patients with or without an extraosseous tumour component, irrespective of grade or anatomical location.

Discussion

The results of this study has shown that the metastatic potential of intraosseous conventional central chondrosarcoma is negligible. The presence of an extraosseous soft tissue component may be used for prognostication and to guide treatment pathways for patients with central cartilage tumours.

Fracture risk after intralesional curettage of atypical cartilaginous tumors

INTRODUCTION

The need for curettage of atypical cartilaginous tumors (ACT) is under debate. Curretage results in defects that weaken the bone potentially leading to fractures. The purpose of this study was to retrospectively determine postoperative fracture risk after curettage of chondroid tumors, including patient-specific characteristics that could influence fracture risk.

METHODS

A total of 297 adult patients who underwent curettage of an ACT followed by phenolisation and augmentation were retrospectively evaluated. Explanatory variables were, sex, age, tumor size, location, augmentation type, and plate fixation. The presence of a postoperative fracture was radiologically diagnosed. Included patients had at least 90 days of follow-up.

RESULTS

A total of 183 females (62%) were included and 114 males (38%), with an overall median follow-up of 3.2 years (IQR 1.6-5.2). Mean diameter of the lesions was 4.5 (SD 2.8) cm. Patients received augmentation with allograft bone (n = 259, 87%), PMMA (n = 11, 3.7%), or did not receive augmentation (n = 27, 9.1%). Overall fracture risk was 6%. Male sex (p = 0.021) and lesion size larger than 3.8 cm (p < 0.010) were risk factors for postoperative fracture.

INTERPRETATION

Curettage of ACT results in an overall fracture risk of 6%, which is increased for males with larger lesions.

The novel dynamic nomogram and risk classification system constructed for predicting post-surgical overall survival and mortality risk in primary chondrosarcoma: a population study based on SEER database

BACKGROUND

Surgery is the predominant method to improve the prognosis of primary chondrosarcoma patients. We aimed to construct the first reliable nomogram to predict the post-surgical overall survival (OS) of primary chondrosarcoma patients.

METHODS

We downloaded all primary chondrosarcoma patients treated with surgery between 2004 and 2015 from the Surveillance, Epidemiology, and End Results (SEER) database, and randomized them into training set (60%) and validation set (40%). Cox proportional regression analysis was applied to the training set to identify independent prognostic variables, and then constructed a nomogram for predicting 3-, 5-, and 8-year OS. The Harrell's concordance index (C-index), receiver operating characteristic curve (ROC), the area under curve (AUC), calibration curve and decision curve analysis (DCA) was used to assess the predictive efficacy and clinical applicability of the nomogram. The nomogram was also compared with The American Joint Committee on Cancer (AJCC) staging system.

RESULTS

A total of 1005 post-surgical primary chondrosarcoma patients were included in this study. We finally identified five independent prognostic variables to construct the nomogram, being age, grade, tumor size, disease stage and histological type. The C-index results showed that the prediction performance of the nomogram was significantly better than the AJCC staging system. In the training set, (C-index: 0.805, 95% CI 0.879-0.730 vs 0.686, 95% CI 0.606-0.766); in the validation set, (C-index: 0.811, 95% CI 0.895-0.727 vs 0.697, 95% CI 0.647-0.799). Additionally, the AUC values generated by the ROC were all greater than 0.8, which also indicated the excellent predictive performance of the nomogram. The calibration curves showed that the predicted survival rate was highly similar to the actual. Time-dependent ROC and DCA showed that the nomogram has better predictive performance and net clinical benefits than the AJCC staging system. Finally, a risk stratification system based on nomogram was constructed.

CONCLUSION

We successfully constructed and validated the first nomogram that could reliably predict 3-, 5-, and 8-year post-surgical OS in primary chondrosarcoma patients. Furthermore, the web-based dynamic nomogram could be more conveniently applied to clinic, providing assistance to surgeons and patients.

Construction of novel predictive tools for post-surgical cancer-specific survival probability in patients with primary chondrosarcoma and external validation in Chinese cohorts: a large population-based retrospective study

BACKGROUND

Surgery is the predominant treatment modality for chondrosarcoma. This study aims to construct a novel clinic predictive tool that accurately predicts the 3-, 5-, and 8-year probability of cancer-specific survival (CSS) for primary chondrosarcoma patients who have undergone surgical treatment.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) database was used to identify 982 primary chondrosarcoma patients after surgery, who were randomly divided into two sets: training set (60%) and internal validation set (40%). Cox proportional regression analyses were used to screen post-surgical independent prognostic variables in primary chondrosarcoma patients. These identified variables were used to construct a nomogram to predict the probability of post-surgical CSS of primary chondrosarcoma patients. The k-fold cross-validation method (k = 10), Harrell's concordance index (C-index), receiver operating characteristic curve (ROC) and area under curve (AUC) were used to assess the predictive accuracy of the nomogram. Calibration curve and decision curve analysis (DCA) were used to validate the clinical application of the nomogram.

RESULTS

Age, tumor size, disease stage and histological type were finally identified post-surgical independent prognostic variables. Based the above variables, a nomogram was constructed to predict the 3-, 5- and 8-year probability of post-surgical CSS in primary chondrosarcoma patients. The results of the C-index showed excellent predictive performance of the nomogram (training set: 0.837, 95% CI: 0.766-0.908; internal validation set: 0.835, 95% CI: 0.733-0.937; external validation set: 0.869, 95% CI: 0.740-0.998). The AUCs of ROC were all greater than 0.830 which again indicated that the nomogram had excellent predictive performance. The results of calibration curve and DCA indicated that the clinical applicability of this nomogram was outstanding. Finally, the risk classification system and online access version of the nomogram was developed.

CONCLUSION

We constructed the first nomogram to accurately predict the 3-, 5- and 8-year probability of post-surgical CSS in primary chondrosarcoma patients. This nomogram would assist surgeons to provide individualized post-surgical survival predictions and clinical strategies for primary chondrosarcoma patients.

Sarcoma Immunotherapy: Confronting Present Hurdles and Unveiling Upcoming Opportunities

Sarcomas are rare and heterogeneous mesenchymal neoplasms originating from the bone or soft tissues, which pose significant treatment challenges. The current standard treatment for sarcomas consists of surgical resection, often combined with chemo- and radiotherapy; however, local recurrence and metastasis remain significant concerns. Although immunotherapy has demonstrated promise in improving long-term survival rates for certain cancers, sarcomas are generally considered to be relatively less immunogenic than other tumors, presenting substantial challenges for effective immunotherapy. In this review, we examine the possible opportunities for sarcoma immunotherapy, noting cancer testis antigens expressed in sarcomas. We then cover the current status of immunotherapies in sarcomas, including progress in cancer vaccines, immune checkpoint inhibitors, and adoptive cellular therapy and their potential in combating these tumors. Furthermore, we discuss the limitations of immunotherapies in sarcomas, including a low tumor mutation burden and immunosuppressive tumor microenvironment, and explore potential strategies to tackle the immunosuppressive barriers in therapeutic interventions, shedding light on the development of effective and personalized treatments for sarcomas. Overall, this review provides a comprehensive overview of the current status and potential of immunotherapies in sarcoma treatment, highlighting the challenges and opportunities for developing effective therapies to improve the outcomes of patients with these rare malignancies.

Dedifferentiated Chondrosarcoma: Diagnostic Controversies and Emerging Therapeutic Targets

PURPOSE OF REVIEW

The pathogenesis of dedifferentiated chondrosarcoma is controversial, and no genetic abnormality has consistently been identified in the disease. Focusing on the diagnostic challenges encountered in dedifferentiated chondrosarcoma, the following review aims at summarizing the tumor's active neoplastic pathways while highlighting therapeutic modalities that could potentially be explored to enhance patient survivorship.

RECENT FINDINGS

Owing to the challenging examination of small needle biopsy sampling as well as the disease's overlapping morphological and immunohistochemical features with other bone and soft-tissue sarcomas, the diagnosis of dedifferentiated chondrosarcoma can be problematic. While combined doxorubicin- and cisplatin-based regimens remain the first-line systemic chemotherapy in the disease, ~50% of tumors carry EXT1/2 or IDH1/2 mutations, advancing EXT or IDH inhibitors as potential alternative therapies, respectively. Despite systemic chemotherapy, dedifferentiated chondrosarcoma remains an aggressive tumor with dismal prognosis and limited survival. A multidisciplinary collaboration across multiple cancer centers is warranted to yield an accurate diagnosis, understand the disease's underlying pathogenesis, develop adequate treatment, and improve patient survivorship.

Proton Therapy for Skull Base Chondrosarcoma

Chondrosarcoma is a type of an endochondral bone malignancy that is primarily treated surgically with radiation therapy used in the adjuvant setting or in cases of unresectable disease. Proton therapy has potential advantages compared with traditional photon therapy for the treatment of tumors in close proximity to critical structures due to the theoretic lower exit dose. Studies have shown improved survival in patients with skull base chondrosarcoma who undergo proton therapy. However, there is a lack of randomized data. Further studies are needed to define the role of proton therapy in the treatment of skull base chondrosarcoma.

Large chondrosarcoma treated successfully with new surgical technique and bone grafts in a 9-year-old girl: Case report

INTRODUCTION

Chondrosarcoma is the second most common after osteosarcoma. It mostly effects adults and elderly individuals, primarily seen in the pelvic and proximal femoral bone. Pain and pathological fractures are common symptoms. The tumor is resistant to radiotherapy and chemotherapy, so surgical excision is the most effective treatment.

CASE PRESENTATION

A 9-year-old girl presented with vague pain in her left thigh. Physical examination and imaging revealed multiple osteolytic lesions in the thigh, and a biopsy confirmed classical chondrosarcoma. The patient underwent surgery, which involved excision of the tumor with a safety margin and the use of a Z-plasty technique. Synthetic graft granules were used to fill the excision area. The patient was followed-up over 8 years without complications and recurrence.

DISCUSSION

Chondrosarcoma is classified based on histological characteristics and clinical behavior. Chondrosarcoma is resistant to chemotherapy and radiation. Treatment options depend on tumor characteristics, and reconstruction may be necessary. For low-grade chondrosarcomas in long bones, intralesional excision and curettage are commonly used, but wide excision may be necessary to minimize recurrence. Vascularized fibular autografts have the potential for weight-bearing, but complications such as fractures and donor site morbidity can occur. Allograft reconstruction may be associated with infection, fracture, delayed or nonunion.

CONCLUSIONS

Treatment approaches vary based on factors such as tumor stage, grade, and location. Each option carries its own risks and complications, including infection, fracture, and delayed healing. This study suggests a new surgical technique using bone grafts.

IDH mutations in G2-3 conventional central bone chondrosarcoma: a mono institutional experience

BACKGROUND

Heterozygous isocitrate dehydrogenase (IDH) mutations occur in about half of conventional central bone chondrosarcomas (CCBC). Aim of this study was to assess the frequency and prognostic impact of IDH mutations in high grade CCBC patients.

METHODS

64 patients with G2 and G3 CCBC were included. DNA extraction, PCR amplification of IDH1/2 exon 4s, and sequencing analysis with Sanger were performed.

RESULTS

IDH mutations were detected in 24/54 patients (44%): IDH1 in 18, IDH2 in 4, and both IDH1/2 in 2 patients. The frequency of mutations was 37% in G2 vs. 69% in G3 (p = 0.039), and 100% in three Ollier disease associated chondrosarcoma. 5-year overall survival (OS) at 124 months (range 1-166) was 51%, with no significant difference based on the IDH mutational status: 61% in IDHmut vs. 44% in IDH wild type (IDHwt). The 5-year relapse free survival (RFS) was 33% (95% CI:10-57) for IDHmut vs. 57% (95%CI: 30-77) for IDHwt. Progression free survival (PFS) was 25% (95%CI:1-65) IDHmut vs. 16% (95%CI: 0.7-52) IDHwt. 55% (5/9) of IDHmut G2 became higher grade at the recurrence, as compared with 25% (3/12) of G2 IDHwt.

CONCLUSIONS

This study shows a higher frequency of IDH mutations in G3 CCBC as compared with G2. No significant differences in OS, RFS, and PFS by mutational status were detected. After relapse, a higher rate of G3 for IDH mutated CCBC was observed.

Mesenchymal Chondrosarcoma from Diagnosis to Clinical Trials

Mesenchymal chondrosarcoma (MCS) is a rare subtype of chondrosarcoma with a poor prognosis. Although these tumors are sensitive to radiotherapy/chemotherapy, the standard treatment for localized MCS is only surgical resection, and there are no established treatment guidelines for patients with advanced and metastatic MCS. Due to the low incidence of MCS, the pathology of these tumors is still unknown, and other therapeutic options are lacking. Some studies show the potential role of the PDGF/PPI3K/AKT, PKC/RAF/MEK/ERK, and pRB pathways, and BCL2 overexpression in the pathogenesis of MCS. These findings provide an opportunity to use protein kinases and BCL2 inhibitors as potential therapy in MCS. In this review, we summarize the current knowledge about MCS diagnosis and treatment options. We show the immunological and molecular biomarkers used in the diagnosis of MCS. In addition, we discuss the known prognostic and predictive factors in MCS. Finally, we present the novel trends, including targeted therapies and ongoing clinical trials using protein kinase inhibitors and the death receptor 5 (DR5) agonist, which may be the focus of future MCS treatment studies.

Risk factors for distant metastasis of chondrosarcoma: A population-based study

Chondrosarcoma is the second largest bone malignancy after osteosarcoma and mainly affects middle-aged adults, where patients with distant metastasis (DM) often have a poor prognosis. Although nomograms have been widely used to predict distant tumor metastases, there is a lack of large-scale data studies for the diagnostic evaluation of DM in chondrosarcoma. Data on patients diagnosed with chondrosarcoma from 2004 to 2015 were obtained from the Surveillance, Epidemiology, and End Results database. Independent risk factors for having DM from chondrosarcoma were screened using univariate and multivariate logistics regression analysis. A nomogram was created to predict the probability of DM from the screened independent risk factors. The nomogram was then validated using receiver operating characteristic curves and calibration curves. A total of 1870 chondrosarcoma patients were included in the study after data screening, of which 157 patients (8.40%) had DM at the time of diagnosis. Univariate and multivariate logistic regression analysis screened four independent risk factors, including grade, tumor number, T stage, and N stage. receiver operating characteristic curves and calibration curves showed good accuracy of the nomogram in both training and validation sets. The current study screened for independent risk factors for DM from chondrosarcoma, which will help clinicians evaluate patients.

In vitro hyperspectral biomarkers of human chondrosarcoma cells in nanoparticle-mediated radiosensitization using carbon ions

New therapeutic approaches are needed for the management of the highly chemo- and radioresistant chondrosarcoma (CHS). In this work, we used polyethylene glycol-encapsulated iron oxide nanoparticles for the intracellular delivery of the chemotherapeutic doxorubicin (IONPDOX) to augment the cytotoxic effects of carbon ions in comparison to photon radiation therapy. The in vitro biological effects were investigated in SW1353 chondrosarcoma cells focusing on the following parameters: cell survival using clonogenic test, detection of micronuclei (MN) by cytokinesis blocked micronucleus assay and morphology together with spectral fingerprints of nuclei using enhanced dark-field microscopy (EDFM) assembled with a hyperspectral imaging (HI) module. The combination of IONPDOX with ion carbon or photon irradiation increased the lethal effects of irradiation alone in correlation with the induction of MN. Alterations in the hyperspectral images and spectral profiles of nuclei reflected the CHS cell biological modifications following the treatments, highlighting possible new spectroscopic markers of cancer therapy effects. These outcomes showed that the proposed combined treatment is promising in improving CHS radiotherapy.

Real-world experience of tyrosine kinase inhibitors in children, adolescents and adults with relapsed or refractory bone tumours: A Canadian Sarcoma Research and Clinical Collaboration (CanSaRCC) study

OBJECTIVES

We conducted a retrospective multi-centre study to assess the real-world outcome of regorafenib (REGO) and cabozantinib (CABO) in recurrent/refractory bone tumours (BTs) including osteosarcoma (OST), Ewing sarcoma (EWS) and chondrosarcoma (CS)/extra-skeletal mesenchymal CS (ESMC).

METHODS

After regulatory approval, data from patients with recurrent BT (11 institutions) were extracted from CanSaRCC (Canadian Sarcoma Research and Clinical Collaboration) database. Patient characteristics, treatment and outcomes were collected. Progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan-Meier method.

RESULTS

From July 2018 to May 2022, 66 patients received REGO or CABO; 39 OST, 18 EWS, 4 CS and 5 ESMC. Median age was 27.8 years (range 12-76); median starting dose was 60 mg for CABO (n = 37, range 40-60) and 120 mg for REGO (n = 29, range 40-160). Twenty-eight (42.4%) patients required dose reduction: hand-foot syndrome 7 (10.6%), nausea/vomiting 1 (1.5%), diarrhoea 1 (1.5%), 2 elevated LFTs (3%), elevated bilirubin 1 (1.5%) and mucositis 1 (1.5%). The median OS for patients with OST, EWS, CS and ESMC was 8.5 months (n = 39, 95% CI 7-13.1); 13.4 months (n = 18, 95% CI 3.4-27.2), 8.1 (n = 4, 95% CI 4.1-9.3) and 18.2 (n = 5, 95% CI (10.4-na), respectively. Median PFS for OST, EWS, CS and ECMS was 3.5 (n = 39, 95% CI 2.8-5), 3.9 (n = 18, 95% CI 2.1-5.9), 5.53 (n = 4. 95% CI 2.13-NA) and 11.4 (n = 5, 95% CI 1.83-14.7), respectively. Age, line of therapy, REGO versus CABO, or time from diagnosis to initiation of TKI were not associated with PFS on univariable analysis.

CONCLUSION

Our real-world data show that TKIs have meaningful activity in recurrent BT with acceptable toxicities when started at modified dosing. Inclusion of TKIs in earlier lines of treatment and/or maintenance therapy could be questions for future research.

MiR-4270 acts as a tumor suppressor by directly targeting Bcl-xL in human osteosarcoma cells

Chondrosarcomas and osteosarcomas are malignant bone tumors with a poor prognosis when unresectable or metastasized. Moreover, radiotherapy and chemotherapy could be ineffective. MiRNAs represent an alternative therapeutic approach. Based on high-throughput functional screening, we identified four miRNAs with a potential antiproliferative effect on SW1353 chondrosarcoma cells. Individual functional validations were then performed in SW1353 cells, as well as in three osteosarcoma cell lines. The antiproliferative and cytotoxic effects of miRNAs were evaluated in comparison with a positive control, miR-342-5p. The cytotoxic effect of four selected miRNAs was not confirmed on SW1353 cells, but we unambiguously revealed that miR-4270 had a potent cytotoxic effect on HOS and MG-63 osteosarcoma cell lines, but not on SaOS-2 cell line. Furthermore, like miR-342-5p, miR-4270 induced apoptosis in these two cell lines. In addition, we provided the first report of Bcl-xL as a direct target of miR-4270. MiR-4270 also decreased the expression of the anti-apoptotic protein Mcl-1, and increased the expression of the pro-apoptotic protein Bak. Our findings demonstrated that miR-4270 has tumor suppressive activity in osteosarcoma cells, particularly through Bcl-xL downregulation.

The landscape of drug sensitivity and resistance in sarcoma

Sarcomas are a family of rare malignancies composed of over 100 distinct histological subtypes. The rarity of sarcoma poses significant challenges in conducting clinical trials to identify effective therapies, to the point that many rarer subtypes of sarcoma do not have standard-of-care treatment. Even for established regimens, there can be substantial heterogeneity in responses. Overall, novel, personalized approaches for identifying effective treatments are needed to improve patient out-comes. Patient-derived tumor organoids (PDTOs) are clinically relevant models representative of the physiological behavior of tumors across an array of malignancies. Here, we use PDTOs as a tool to better understand the biology of individual tumors and characterize the landscape of drug resistance and sensitivity in sarcoma. We collected n=194 specimens from n=126 sarcoma patients, spanning 24 distinct subtypes. We characterized PDTOs established from over 120 biopsy, resection, and metastasectomy samples. We leveraged our organoid high-throughput drug screening pipeline to test the efficacy of chemotherapeutics, targeted agents, and combination therapies, with results available within a week from tissue collection. Sarcoma PDTOs showed patient-specific growth characteristics and subtype-specific histopathology. Organoid sensitivity correlated with diagnostic subtype, patient age at diagnosis, lesion type, prior treatment history, and disease trajectory for a subset of the compounds screened. We found 90 biological pathways that were implicated in response to treatment of bone and soft tissue sarcoma organoids. By comparing functional responses of organoids and genetic features of the tumors, we show how PDTO drug screening can provide an orthogonal set of information to facilitate optimal drug selection, avoid ineffective therapies, and mirror patient outcomes in sarcoma. In aggregate, we were able to identify at least one effective FDA-approved or NCCN-recommended regimen for 59% of the specimens tested, providing an estimate of the proportion of immediately actionable information identified through our pipeline.

Highlights

Standardized organoid culture preserve unique sarcoma histopathological featuresDrug screening on patient-derived sarcoma organoids provides sensitivity information that correlates with clinical features and yields actionable information for treatment guidanceHigh-throughput screenings provide orthogonal information to genetic sequencingSarcoma organoid response to treatment correlates with patient response to therapyLarge scale, functional precision medicine programs for rare cancers are feasible within a single institution.

Dedifferentiated Chondrosarcoma from Molecular Pathology to Current Treatment and Clinical Trials

Dedifferentiated chondrosarcoma (DDCS) is a rare subtype of chondrosarcoma, a primary cartilaginous malignant neoplasm. It accounts for up to 1-2% of all chondrosarcomas and is generally associated with one of the poorest prognoses among all chondrosarcomas with the highest risk of metastasis. The 5-year survival rates range from 7% to 24%. DDCS may develop at any age, but the average presentation age is over 50. The most common locations are the femur, pelvis humerus, scapula, rib, and tibia. The standard treatment for localised disease is surgical resection. Most patients are diagnosed in unresectable and advanced stages, and chemotherapy for localised and metastatic dedifferentiated DDCS follows protocols used for osteosarcoma.

Operative Treatment and Outcomes of Pediatric Patients with an Extremity Bone Tumor: A Secondary Analysis of the PARITY Trial Data

BACKGROUND

Osteosarcoma and Ewing sarcoma are the 2 most common primary bone sarcomas, occurring predominantly in pediatric patients, with the incidence of osteosarcoma correlating with periods of peak bone-growth velocity. Although survival outcomes have plateaued over the past several decades, ongoing treatment advances have improved function, decreased infection rates, and improved other clinical outcomes in patients with bone tumors. Recently, the Prophylactic Antibiotic Regimens in Tumor Surgery (PARITY) trial addressed the serious problem of surgical site infection (SSI) and the lack of consensus regarding the appropriate prophylactic postoperative antibiotic regimen. The objective of the present secondary analysis of the PARITY trial was to characterize the modern treatment and surgical and oncologic outcomes of pediatric patients with bone tumors at 1 year postoperatively.

METHODS

The PARITY trial included patients ≥12 years old with a bone tumor or soft-tissue sarcoma that was invading the femur or tibia, necessitating osseous resection and endoprosthetic reconstruction. This pediatric subanalysis of the PARITY trial data included all PARITY patients ≤18 years old. As in the main PARITY study, patients were randomized to either a 5-day or 1-day course of postoperative antibiotic prophylaxis. The primary outcome measure was the development of an SSI within 1 year, and secondary outcomes included antibiotic-related adverse events, unplanned additional operations, local recurrence, metastasis, and death.

RESULTS

A total of 151 patients were included. An adjudicated SSI occurred in 27 patients (17.9%). There was no difference in the rate of any SSI between the 5-day and 1-day antibiotic groups (hazard ratio [HR], 0.92; 95% confidence interval [CI], 0.4 to 1.9; p = 0.82). Antibiotic-related complications occurred in 13 patients (8.6%), with no difference noted between groups (HR, 0.46; 95% CI, 0.2 to 1.4; p = 0.18). A total of 45 patients (29.8%) required a return to the operating room within the first postoperative year, which corresponded with a 68.8% reoperation-free rate of survival at 1 year when accounting for competing risks. The most common reason for reoperation was infection (29 of 45; 64.4%). A total of 7 patients (4.6%) required subsequent amputation of the operative extremity, and an additional 6 patients (4.0%) required implant revision within 12 months. A total of 36 patients (23.8%) developed metastases, and 6 patients (4.0%) developed a local recurrence during the first postoperative year. A total of 11 patients (7.3%) died during the study period. There were no significant differences in oncologic outcomes between the 5-day and 1-day antibiotic groups (HR, 0.97; 95% CI, 0.5-1.8; p = 0.92).

CONCLUSIONS

There were no significant differences in surgical or oncologic outcomes between pediatric patients who underwent a 1-day versus 5-day antibiotic regimen following endoprosthetic reconstruction in the PARITY trial. Surgeons should be aware of and counsel patients and caregivers regarding the 30% rate of reoperation and the risks of infection (17.9%), death (7.3%), amputation (4.6%), and implant revision (4%) within the first postoperative year.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

IDH Mutations in Chondrosarcoma: Case Closed or Not?

Chondrosarcomas are malignant cartilage-producing tumours that frequently harbour isocitrate dehydrogenase 1 and -2 (IDH) gene mutations. Several studies have confirmed that these mutations are key players in the early stages of cartilage tumour development, but their role in later stages remains ambiguous. The prognostic value of IDH mutations remains unclear and preclinical studies have not identified effective treatment modalities (in)directly targeting these mutations. In contrast, the IDH mutation status is a prognostic factor in other cancers, and IDH mutant inhibitors as well as therapeutic strategies targeting the underlying vulnerabilities induced by IDH mutations seem effective in these tumour types. This discrepancy in findings might be ascribed to a difference in tumour type, elevated D-2-hydroxyglutarate levels, and the type of in vitro model (endogenous vs. genetically modified) used in preclinical studies. Moreover, recent studies suggest that the (epi)genetic landscape in which the IDH mutation functions is an important factor to consider when investigating potential therapeutic strategies or patient outcomes. These findings imply that the dichotomy between IDH wildtype and mutant is too simplistic and additional subgroups indeed exist within chondrosarcoma. Future studies should focus on the identification, characterisation, and tailoring of treatments towards these biological subgroups within IDH wildtype and mutant chondrosarcoma.

Complications and Functional Outcome Differences in Carbon Ion Radiotherapy and Surgery for Malignant Bone Tumors of the Pelvis: A Multicenter, Cohort Study

BACKGROUND

Carbon ion radiotherapy (CIRT) is an evolving treatment option for malignant pelvic tumors in patients with poor surgical indications. However, the difference in complications and functional outcomes between CIRT and surgery is poorly understood. This study compares the complications and functional outcomes of CIRT and surgery to facilitate treatment selection.

METHODS

A total of 28 patients who underwent CIRT for pelvic bone tumors while theoretically meeting the surgical resection criteria were included. Sixty-nine patients who underwent surgery for pelvic bone tumors were included as controls. Major complication rates and functional outcomes (ambulatory, pain, urination, constipation) were evaluated and compared at several time points (pretreatment, discharge, and final follow-up) between the groups.

RESULTS

Early (within 90 days) major complications were not observed in the CIRT group but occurred in 30% of the surgery group, which was statistically significant (P < 0.001). In contrast, late (after 90 days) major complications occurred more often in the CIRT group than in the surgery group (18% and 4%, respectively; P = 0.042). From pretreatment until discharge, all functional outcomes in the surgery group deteriorated (P < 0.001 for all) but did not change in the CIRT group (P = 0.77-1.00). At the final follow-up, all functional outcomes showed no significant intergroup difference (P = 0.28-0.92) due to the recovery trend in the surgery group and the deterioration trend in the CIRT group.

CONCLUSIONS

Compared with surgery, CIRT may have favorable safety and stable functional outcomes in the short-term but more late complications. Mid-term functional outcomes were similar between the groups.

Is a radiological score able to predict resection-grade chondrosarcoma in primary intraosseous lesions of the long bones?

Aims

The preoperative grading of chondrosarcomas of bone that accurately predicts surgical management is difficult for surgeons, radiologists, and pathologists. There are often discrepancies in grade between the initial biopsy and the final histology. Recent advances in the use of imaging methods have shown promise in the ability to predict the final grade. The most important clinical distinction is between grade 1 chondrosarcomas, which are amenable to curettage, and resection-grade chondrosarcomas (grade 2 and 3) which require en bloc resection. The aim of this study was to evaluate the use of a Radiological Aggressiveness Score (RAS) to predict the grade of primary chondrosarcomas in long bones and thus to guide management.

Methods

A total of 113 patients with a primary chondrosarcoma of a long bone presenting between January 2001 and December 2021 were identified on retrospective review of a single oncology centre's prospectively collected database. The nine-parameter RAS included variables from radiographs and MRI scans. The best cut-off of parameters to predict the final grade of chondrosarcoma after resection was determined using a receiver operating characteristic curve (ROC), and this was correlated with the biopsy grade.

Results

A RAS of ≥ four parameters was 97.9% sensitive and 90.5% specific in predicting resection-grade chondrosarcoma based on a ROC cut-off derived using the Youden index. Cronbach's α of 0.897 was derived as the interclass correlation for scoring the lesions by four blinded reviewers who were surgeons. Concordance between resection-grade lesions predicted from the RAS and ROC cut-off with the final grade after resection was 96.46%. Concordance between the biopsy grade and the final grade was 63.8%. However, when the patients were analyzed based on surgical management, the initial biopsy was able to differentiate low-grade from resection-grade chondrosarcomas in 82.9% of biopsies.

Conclusion

These findings suggest that the RAS is an accurate method for guiding the surgical management of patients with these tumours, particularly when the initial biopsy results are discordant with the clinical presentation.

Mutant IDH regulates glycogen metabolism from early cartilage development to malignant chondrosarcoma formation

Chondrosarcomas are the most common malignancy of cartilage and are associated with somatic mutations in isocitrate dehydrogenase 1 (IDH1) and IDH2 genes. Somatic IDH mutations are also found in its benign precursor lesion, enchondromas, suggesting that IDH mutations are early events in malignant transformation. Human mutant IDH chondrosarcomas and mutant Idh mice that develop enchondromas investigated in our studies display glycogen deposition exclusively in mutant cells from IDH mutant chondrosarcomas and Idh1 mutant murine growth plates. Pharmacologic blockade of glycogen utilization induces changes in tumor cell behavior, downstream energetic pathways, and tumor burden in vitro and in vivo. Mutant IDH1 interacts with hypoxia-inducible factor 1α (HIF1α) to regulate expression of key enzymes in glycogen metabolism. Here, we show a critical role for glycogen in enchondromas and chondrosarcomas, which is likely mediated through an interaction with mutant IDH1 and HIF1α.

Chondrosarcoma of the hyoid bone: a case of mistaken identity in the submandibular region

We describe a case of woman in her 60s who presented with a painless mass in her left submandibular region that biopsies and imaging suggested was a pleomorphic adenoma. Intraoperative findings showed a submandibular mass originating from the hyoid bone, and subsequent histopathological examination showed a grade 2 chondrosarcoma of the hyoid bone. Chondrosarcomas in the head and neck region are uncommon and presentations in the hyoid bone are very rare with only approximately 27 previously published cases. Presentations that pose as more benign pathology can cause diagnostic dilemmas for clinicians.

miRNAs as potential game-changers in bone diseases: Future medicinal and clinical uses

MicroRNAs (miRNAs), short, highly conserved non-coding RNA, influence gene expression by sequential mechanisms such as mRNA breakdown or translational repression. Many biological processes depend on these regulating substances, thus changes in their expression have an impact on the maintenance of cellular homeostasis and result in the emergence of a variety of diseases. Relevant studies have shown in recent years that miRNAs are involved in many stages of bone development and growth. Additionally, abnormal production of miRNA in bone tissues has been closely associated with the development of numerous bone disorders, such as osteonecrosis, bone cancer, and bone metastases. Many pathological processes, including bone loss, metastasis, the proliferation of osteosarcoma cells, and differentiation of osteoblasts and osteoclasts, are under the control of miRNAs. By bringing together the most up-to-date information on the clinical relevance of miRNAs in such diseases, this study hopes to further the study of the biological features of miRNAs in bone disorders and explore their potential as a therapeutic target.

Chondrosarcoma of the Proximal Humerus: Does the Margin Affect Survival?

Chondrosarcoma (CS) is the second most common primary malignant bone tumour and, in the absence of reliable chemotherapy and radiotherapy, is effectively a surgical disease. Overall disease specific survival (DSS) is affected by tumour grade, whilst resection margin contributes to local recurrence free survival (LRFS). The aim of this study was to investigate factors that affect the local and systemic prognoses for conventional central CSs arising from the proximal humerus. A multi-centre, retrospective study from three international collaborative sarcoma centres identified 110 patients between 1995 and 2020 undergoing treatment for a conventional central CS of the proximal humerus; 58 patients (53%) had a grade 1 tumour, 36 (33%) had a grade 2 tumour, and 16 patients (13%) had a grade 3 CS. The mean age of patients was 50 years (range 10-85). The incidence of local recurrence (LR) was 9/110 (8.2%), and the disease specific mortality was 6/110 (5.5%). The grade was a statistically significant factor for LRFS (p < 0.001). None of the grade 1 tumours developed LR. The DSS was affected by the grade (p < 0.001) but not by the LR (p = 0.4). Only one patient with a grade 2 tumour died from the disease. The proximal humeral grade 1 CS behaved as a benign tumour, having no cases of LR nor death due to disease. Grade 2 CSs of the proximal humerus behaved in a more indolent way when compared with comparable grade tumours elsewhere in the appendicular skeleton, being locally aggressive with a higher LR rate than grade 1 CSs but still having very low mortality and a high rate of DSS. The LR in grade 2 CSs did not affect the DSS; therefore, surgical management in proximal humeral grade 2 CSs should have a greater emphasis on preserving function whilst maintaining an adequate margin for resection. The proximal humeral grade 3 CS was, as elsewhere in the skeleton, an aggressive, high-grade tumour. Therefore, surgical management should include en bloc resection with clear margins to avoid LR.

Conventional Chondrosarcoma of the Rib Cage and Sternum: Clinicopathological and Molecular Analysis of 27 Patients Treated at a Single Institution

Conventional chondrosarcoma of the chest wall is rare, accounting for 15% of cases. Our purpose was to document clinicopathological, imaging and outcome results from a novel set of chest wall chondrosarcomas, and to analyze for <I>IDH</I> mutations and novel molecular alterations. Gross and microscopic pathology, imaging and clinical charts were reviewed. Targeted next-generation sequencing was performed to identify somatic mutations and copy number alterations. The cohort consisted of 27 patients: 16 men and 11 women (mean age 51 years; range 23-76). Palpable mass was the most common presentation. Five were discovered incidentally. Among 20 tumors with complete imaging, 15 arose from a rib and 5 from the sternum. Seven rib tumors were central/intramedullary, 5 were periosteal, 2 were secondary peripheral chondrosarcomas, and one was indeterminate. Among sternal tumors, 4 were central/intramedullary and one was periosteal. Half the periosteal tumors arose from the costochondral junctional cartilage (CCJ). Periosteal chondrosarcomas were sometimes mistaken for extraskeletal masses on initial clinical or radiological examinations. Fifty-nine percent of all tumors were grade 1 and 41% were grade 2. None were dedifferentiated chondrosarcomas. Heterozygous <I>IDH1</I> mutation was detected in one tumor and heterozygous <I>RAD50</I> mutation in another. Local recurrence(s) happened in 41% and metastasis in 41%. Grade had strong association with local recurrence (25% grade 1 vs. 64% grade 2 [p=0.0447]), metastatic recurrence (19% grade 1 vs. 73% grade 2 [p=0.0058]), and survival. Although chest wall chondrosarcomas share morphologic and molecular features with other chondrosarcomas, there is a much higher incidence of periosteal chondrosarcomas. <I>IDH</I> mutant tumors are uncommon. Early diagnosis and margin-negative resection is treatment of choice since chondrosarcomas are chemo- and radioresistant.

Intracranial Metastasis of Extracranial Chondrosarcoma: Systematic Review With Illustrative Case

BACKGROUND

Cerebral chondrosarcoma metastases are rare and aggressive neoplasms. The rarity of presentation has precluded rigorous analysis of diagnosis, risk factors, treatment, and survival. We analyzed every reported case through exhaustive literature review. We further present the first case with Maffucci syndrome.

METHODS

Three databases, PubMed, Embase, and Google Scholar, and crossed references were queried for cerebral chondrosarcoma metastases. Extracted variables included demographics, risk factors, tumor characteristics, interventions, and outcomes. Univariate and multivariate analyses were performed.

RESULTS

Fifty-six patients were included from 1,489 literature results. The average age at brain metastasis was 46.6±17.6 years and occurred at a median of 24±2.8 months from primary diagnosis. Primary tumor histology (dedifferentiated 5.0±1.5 months, mesenchymal 24±3.0 months, conventional 41±7.4 months, p<0.05) and grade (low grade 54±16.7 months vs. high-grade 10±6.4 months, p<0.001) correlated with time interval until brain metastasis. A multiple enchondromatosis syndrome occurred in 13.2% of cases. At time of brain metastases diagnosis, extracranial metastases were identified in 76.2% of cases. Median survival after the development of brain metastasis was 2.0±0.78 months with a 1-year survival of 10.0%. On regression analysis, surgery reduced brain metastasis mortality risk and radiation trended towards reduced mortality risk (surgery: hazard ratio [HR] 0.22, 95% confidence interval [CI] 0.064-0.763, p=0.017; radiation: HR 0.31, 95% CI 0.091-1.072, p=0.064).

CONCLUSION

We present a systematic review of cerebral chondrosarcoma metastases. Primary tumor histology and grade correlate with time until cerebral metastasis. Following cerebral metastasis, these tumors have poor prognosis and modestly benefit from surgery.

Chondrosarcoma Resistance to Radiation Therapy: Origins and Potential Therapeutic Solutions

Chondrosarcoma is a malignant cartilaginous tumor that is particularly chemoresistant and radioresistant to X-rays. The first line of treatment is surgery, though this is almost impossible in some specific locations. Such resistances can be explained by the particular composition of the tumor, which develops within a dense cartilaginous matrix, producing a resistant area where the oxygen tension is very low. This microenvironment forces the cells to adapt and dedifferentiate into cancer stem cells, which are described to be more resistant to conventional treatments. One of the main avenues considered to treat this type of tumor is hadrontherapy, in particular for its ballistic properties but also its greater biological effectiveness against tumor cells. In this review, we describe the different forms of chondrosarcoma resistance and how hadrontherapy, combined with other treatments involving targeted inhibitors, could help to better treat high-grade chondrosarcoma.

Treatment of Osteoporosis With Anabolic Agents and the Risk of Primary Bone Cancers: A Study of 44,728 Patients Treated With Teriparatide and Abaloparatide

INTRODUCTION

Bone anabolic agents can benefit orthopaedic patients perioperatively and improve outcomes after fragility fractures. However, preliminary animal data raised concern for the potential development of primary bony malignancies after treatment with these medications.

METHODS

This investigation examined 44,728 patients older than 50 years who were prescribed teriparatide or abaloparatide and compared them with a matched control group to evaluate risk of primary bone cancer development. Patients younger than 50 years with a history of cancer or other risk factors of bony malignancy were excluded. A separate cohort of 1,241 patients prescribed an anabolic agent with risk factors of primary bone malignancy, along with 6,199 matched control subjects, was created to evaluate the effect of anabolic agents. Cumulative incidence and incidence rate per 100,000 person-years were calculated as were risk ratios and incidence rate ratios.

RESULTS

The overall risk of primary bone malignancy development for risk factor-excluded patients in the anabolic agent-exposed group was 0.02%, compared with 0.05% in the nonexposed group. The incidence rate per 100,000 person-years was calculated at 3.61 for the anabolic-exposed patients and 6.46 for control subjects. A risk ratio of 0.47 (P = 0.03) and incidence rate ratio of 0.56 (P = 0.052) were observed for the development of primary bone malignancies in patients undergoing treatment with bone anabolic agents. Among high-risk patients, 5.96% of the anabolic-exposed cohort developed primary bone malignancies and 8.13% of nonexposed patients developed primary bone malignancy. The risk ratio was 0.73 (P = 0.01), and the incidence rate ratio was 0.95 (P = 0.67).

CONCLUSION

Teriparatide and abaloparatide can safely be used for osteoporosis and orthopaedic perioperative management without increased risk of development of primary bone malignancy.

Classification of Chondrosarcoma: From Characteristic to Challenging Imaging Findings

Chondrosarcomas can be classified into various forms according to the presence or absence of a precursor lesion, location, and histological subtype. The new 2020 World Health Organization (WHO) Classification of Tumors of Soft Tissue and Bone classifies chondrogenic bone tumors as benign, intermediate (locally aggressive), or malignant, and separates atypical cartilaginous tumors (ACTs) and chondrosarcoma grade 1 (CS1) as intermediate and malignant tumors. respectively. Furthermore, the classification categorizes chondrosarcomas (including ACT) into eight subtypes: central conventional (grade 1 vs. 2–3), secondary peripheral (grade 1 vs. 2–3), periosteal, dedifferentiated, mesenchymal, and clear cell chondrosarcoma. Most chondrosarcomas are the low-grade, primary central conventional type. The rarer subtypes include clear cell, mesenchymal, and dedifferentiated chondrosarcomas. Comprehensive analysis of the characteristic imaging findings can help differentiate various forms of chondrosarcomas. However, distinguishing low-grade chondrosarcomas from enchondromas or high-grade chondrosarcomas is radiologically and histopathologically challenging, even for experienced radiologists and pathologists.

Bone and soft tissue tumors at the borderlands of malignancy

This review examines findings of musculoskeletal neoplasms whose equivocal imaging and/or histopathologic features make it difficult to determine if they will show aggressive behavior. We include both intermediate tumors as defined by the World Health Organization (WHO), and a single low-grade malignancy, low-grade central osteosarcoma, which mimics a benign lesion on imaging and histology. Intermediate tumors are a broad category and are subdivided into tumors that have risk of local recurrence only, and ones that have a risk of distant limb and pulmonary metastases. Difficult intermediate musculoskeletal lesions include atypical cartilaginous tumor/grade 1 chondrosarcoma, atypical lipomatous tumor/grade 1 liposarcoma, and solitary fibrous tumor. We review diagnostic criteria, differential diagnosis, and recommendations for surveillance.

The occurrence of bone and joint cancers and their association with rural living and radon exposure in Iowa

Primary bone and joint cancers are rare and understudied, yet these neoplasms are difficult to treat and impact all age groups. To explore the long-term changes in the occurrence of bone and joint cancers, patients diagnosed with these neoplasms between 1975 and 2016 were identified in the Surveillance Epidemiology and End Results of the National Cancer Institute of the USA. The age-adjusted incidence (AAIR) and mortality (AAMR) rates were calculated for three decades and compared to AAIR and AAMR in years 1975-1984. By using the population-based cancer registries of the USA, Iowa was identified as a state with increased cases of bone and joint malignancies. The bone and joint cancer cases in Iowa were correlated with the percentage of rural population, the average farmland size, or the residential radon levels. Results demonstrated that the mean AAIR of bone and joint cancers for US female and male patients (< 50 years of age) increased from 0.57 (95% C.I. 0.55-0.63) and 0.76 (95% C.I. 0.69-0.82) for years 1975-1984 to 0.71 (95% C.I. 0.66-0.76) and 0.94 (95% C.I. 0.87-1.07) for years 2005-2014, respectively. The increase in bone and joint cancer cases in Iowa positively correlated with the percentage rural population (R = 0.222, P < 0.02), and the average farmland size (R = 0.236, P < 0.02) but not the radon levels (R = - 0.038, P < 0.7). The findings revealed that patients younger than 50 years of age and those who resided in rural areas and engaged in farming were more likely to be diagnosed with primary bone and joint cancers.